OUR HAS STARTED TO MAKE A WHIRRING NOISE WHEN WE ACCELERATE. WHAT COULD BE CAUSING THIS?

2005 GMC Envoy • 105,000 miles

We have an V8 Envoy Denali. It makes a whirring noise when we accelerate. It sounds like an airplane. This is something new that start less then a 1,000 miles ago. We've read it could be cooling fan clutch failure.

The vehicle has to be moving for the noise to happen. It's drive train related because the noise does not mimic the RPM of the engine. It sounds like it could be coming out of the rear axle but not sure.

Noisy front bearings are real common. It's also common for noise to travel and be heard away from the source. The only way I've found to determine which one is noisy is to run it in gear on a hoist and listen with a stethoscope.

A different approach is to use a "Chassis Ear". You might be able to borrow or rent one from an auto parts store that borrows tools. It is a set of six microphones, a switch box, and headphones. You clip the microphones to suspect points, then drive around while listening with the headphones. You can move the microphones around to zero in on the source of the noise. Be aware that many mechanics have never seen or even heard of this tool. Suspension and alignment mechanics use it to find rattles, squeaks, and other noises.